Truck/trailer box constructions

ABSTRACT

A wall structure of a trailer box ( 10 ) is constructed from a plurality of panels ( 36, 38, 40 ) which are welded together where their edges meet. The panels ( 36, 38, 40 ) are each extrusions and each includes thin side skins ( 42, 44 ) and thin webs ( 46, 48, 50 ). The edge regions that are connected together include thickened portions that dissipate a substantial amount of the heat provided by the welds ( 56, 58 ). A plurality of panels ( 36, 38, 40 ) are welded together to form a large wall structure (WS). This wall structure (WS) is then reconfigured by a roll-forming machine (FIGS.  8-10 ) to provide a box ( 10 ) having a longitudinally straight and laterally curved configuration. Laterally considered, the box ( 10 ) has a concave inner side and a convex outer side. This shape of the box provides the box with both sidewalls and a bottom. The overall construction of the trailer box is lightweight and quite strong and facilitates construction of the truck/trailer box.

RELATED APPLICATION

This application is a continuation-in-part of my pending applicationSer. No. 09/754,705, filed Jan. 4, 2001, and entitled TRUCK/TRAILER BOXCONSTRUCTIONS.

TECHNICAL FIELD

This invention relates generally to a truck/trailer box constructionhaving a sidewall structure that is longitudinally straight andlaterally curved, and having a concave inside shape and a convex outsideshape. More particularly, it relates to the provision of such a sidewallstructure that is formed from spaced apart inner and outer skins andlongitudinally spaced apart webs that extend between and interconnectthe two skins. It also relates to a method of making the sidewallstructure and a truck/trailer box utilizing the sidewall structure.

BACKGROUND OF THE INVENTION

Known truck/trailer boxes that are longitudinally straight and laterallycurved, and which have a concave upper side and a convex lower side, areshown by the following U.S. Pat. No. 1,805,489, granted May 19, 1931, toArthur G. Kerr and Daniel Merchant; U.S. Pat. No. 3,844,616, grantedOct. 29, 1974, to Douglas B. Acre; U.S. Pat. No. 4,948,155, granted Aug.14, 1990, to Fred T. Smith and Fred P. Smith; U.S. Pat. No. 5,090,773,granted Feb. 25, 1992, to Bernard Guillsume; and U.S. Pat. No.5,482,359, granted Jan. 9, 1996, to Albert A. Goodson. These patentsshould be carefully considered for the purpose of putting the presentinvention into proper prospective relative to the prior art.

There is a need for a way of constructing the sidewalls of thetruck/trailer boxes from materials that are very lightweight but yet arestrong and rigid. There is also a need for such a truck/trailer boxconstruction that permits the sidewall to be built in sections that canbe welded together while allowing for the use of very thin skins andwebs that are themselves too thin to be welded. A principal object ofthe present invention is to fulfill these needs.

BRIEF SUMMARY OF THE INVENTION

A truck/trailer box construction of the present invention comprises alongitudinally straight sidewall structure having a laterally concaveinside shape and a laterally convex outside shape. The sidewallstructure comprises spaced apart inner and outer skins andlongitudinally spaced apart webs, extending between and interconnectingthe two skins. In preferred form, the sidewall structure is formed froma series of panels that are welded together at edges where they meet.Preferably, the upper and lower skins and the webs are constructed froman aluminum alloy material, or the like, and are formed by extrusion.

The method of the present invention is basically characterized byproviding a sidewall panel structure that includes an upper skin, alower skin and a plurality of parallel, longitudinally spaced apart,webs, which extend between and interconnect the skins. This sidewallpanel structure is roll formed to give it a longitudinally straight andtransversely curved shape. To do this, a plurality of forming rolls areprovided in a cluster. Adjacent rolls form nips for receiving the panelstructure. The panel structure is fed into the nips, with their websdisposed substantially perpendicular to the axis of the rolls. Thesidewall panel structure is fed through the rolls several times in orderto bend the wall structure a small amount each run through.

The present invention provides a truck/trailer box construction in whichthe floor and the sides of the box are created without a seam or a weldjoint connecting them together. A plurality of long extrusions are usedto create the floor and the sides of the box. The extrusions are weldedtogether at their edges to form a single large panel structure that isthen transformed by roll forming into a substantially semi cylindricalshape. The resulting box structure preferably has substantially flatupper side portions that extend the full length of the box above theportion of the panel structure that is roll formed. Herein the structurethat is formed by welding a plurality of elongated panels together isreferred to as sidewall structure even though it also forms a bottom forthe box when it is reconfigured by roll forming.

The present invention also permits the elimination of longitudinalsupports or stiffeners for the panels that are normally a part of theprior art boxes, which have rounded bottom. The longitudinal supportsand/or stiffeners are not needed because the sidewall structure isstiffened by the skins and the webs that extend between and interconnectthe skins. The webs are in effect ribs inside the sidewall structure andthey are sufficient to provide the strength and stiffening that thesidewall structure needs.

The present invention includes constructing a truck/trailer box frompanels of aluminum extrusions and welding the panels together in a waythat minimizes loss of strength caused by heat from the welds. In thepanel and joint construction of the invention, a substantial part of theheat dissipates in two webs that meet at the joint and in thickenedcorner regions formed where the webs meet the skins of the panels. Thedissipation of the heat from the weld in these regions minimize heatdissipation in the skins of the panel away from the joints wherestrength is needed.

Other objects, advantages and features of the invention will becomeapparent from the description of the best mode that is set forth below,from the drawings, from the claims and from the principals that areembodied in the specific structures that are illustrated and described.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Like reference numerals are used to designate like parts throughout theseveral views of the drawing, and:

FIG. 1 is a fragmentary side elevational view of one embodiment of theinvention, such view showing foreground portions of the truck/trailerbox, and a housing within the box, both cut away for the purpose ofshowing a portion of a cylinder that is provided for raising andlowering the box relative to the truck/trailer frame:

FIG. 2 is a pictorial view of the truck/trailer box shown by FIG. 1,such view looking towards the front and one side of the box;

FIG. 3 is an exploded pictorial view of the truck/trailer box shown byFIGS. 1 and 2;

FIG. 4 is a fragmentary sectional view taken substantially along line4—4FIG. 1;

FIG. 5 is a side elevation view of a second embodiment of the invention;

FIG. 6 is a fragmentary pictorial view showing the lifting cylinderbeing used to tilt the truck/trailer box upwardly from a truck/trailerframe;

FIG. 7 is a transverse sectional view taken substantially along line 7—7of FIG. 5, but with the truck/trailer frame omitted;

FIG. 7A is an enlarged scale sectional view taken substantially alongline 7A—7A of FIG. 4;

FIG. 8 is an end view showing a thin skinned, hollow core panel,positioned to enter into the forming rolls of a roll forming machine;

FIG. 9 is a view like FIG. 8, but showing the panel in the process ofbeing bent by the forming rolls:

FIG. 10 is a view like FIGS. 8 and 10, but showing a final stage of rollforming the panel to form the sidewall of the truck/trailer box;

FIG. 11 is an enlarged scale end elevational view showing confrontingedges of adjacent extrusions spaced from each other; and

FIG. 12 is a view like FIG. 11, but showing the two edges of theextrusions together and further showing welds connecting the extrusionstogether where they meet.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a truck/trailer box 10 mounted on a truck/trailer chassis12. Box 10 includes a sidewall structure 14, a base frame 16, a frontwall 18, and a rear door 20. The base frame 16 is hinge connected at 22to the chassis frame 12. A hydraulic cylinder 24 is pin connected at itslower end to the chassis frame 12 and at its upper end to the box 10. Itserves to raise and lower the box 10 relative to the chassis frame 12.Cylinder 24 is shown in a retracted position in FIG. 1. It includes apiston component 26 and a cylinder component 28. The base in thecylinder component 28 is connected to the frame structure 12 by a pivotpin 30. The upper end of the piston rod component is connected to ahousing 32 by a pivot pin 34. The inner housing 32 is provided toreceive the cylinder 24. In FIG. 3, housing 32 is shown outside of thesidewall structure 14.

FIG. 1 shows the cylinder 24 retracted and the box 10 resting on thechassis frame 12. When cylinder 24 is extended, the piston rod component26 moves upwardly out of the cylinder component 38 and pushes up on theupper forward end portion of the box 10. This causes the box 10 to swingupwardly about pivot pin 22 into a rearward tilting position.

Referring to FIG. 3, the first embodiment has a sidewall structure 14that is constructed from three panels 36, 38, 40. Each panel 36, 38, 40includes an inner skin 42, an outer skin 44 and a plurality of webs 46,48, 50. A typical panel has one web 48, one web 50 and twelve webs 46.Panels 36, 38, 40 are formed by extrusion. The webs 46, 48, 50 extendlongitudinally of the panels 36, 38, 40 when the panels 36, 38, 40 arestill flat and straight. Preferably, the flat panels 36, 38, 40 arebrought together at their edges. The web 48 on panel 36 is mated withthe web 50 on panel 38. In similar fashion, the web 48 on panel 38 ismated with the web 50 on panel 40. The webs 50 include longitudinaltongues 52 that fit inside of longitudinal grooves 54 formed in the webs48. The outside corner regions of webs 48, 50 are beveled [FIG. 4] andwhen a web 48 is mated with a web 50, a v-groove is provided by thebevels on both the inside 42 and the outside 44 of the two panels beingjoined. Following mating of each web 48 with a web 50, the v-groove arewelded, so as to form filet welds 56 on the inside of the panels andfilet welds 58 on the outside of the panels. The welds 56, 58 and thecross sectional configuration of the webs 48, 50 provide a sectionalshape at the joints that bares similarity to an I-beam. Each such I-beamregion is an integral part of the joint and hence is an integral part ofthe sidewall structure. The panel and joint construction used in thewall structure of the present invention is essentially like the paneland wall construction disclosed in the aforementioned co-pendingapplication Ser. No. 09/754,705. The contents of that application arehereby incorporated in the application by this specific reference, underthe doctrine of incorporation by reference.

When the panels 36, 38, 40 are joined and welded together, they form asidewall structure that is flat. This structure is as long as thecombined widths of the panels 36, 38, 40 and is as wide as the commonlength of the panels 36, 38, 40. After the panels 36, 38, 40 are weldedtogether, to form a unitary structure composed of a skin on each sideand a plurality of webs interconnecting the skins, the wall structure isroll formed into a shape that is close to being semi cylindrical. By wayof typical and therefore non-limitive example, the roll forming can bedone by use of a standard plate roller, for example, such as are made byThe Webb Corporation having a business address of 402 East Broadway,Webb City, Mo. 64870. FIGS. 8-10 are end views of a Webb three rollbending machine. This equipment comprises rolls 1, 2, 3. FIG. 8 showsthe wall structure WS being moved towards a nip that is formed by andbetween rolls 1 and 2. A second nip is formed by and between rolls 1 and3. The wall structure WS is oriented with the webs 46, 48, 50perpendicular to the axes of rotation of the rolls 1, 2, 3. Thus, thebending that is done bends both the skins 42, 44 and the webs 46, 48,50. Referring to FIG. 9, the rolls 1 and 2 move the wall structure WSinto contact with the roll 3. Bending does not commence immediately andso the leading portion of the wall structure WS, designated 60, remainsflat. The amount of curvature caused by each run through of the wallstructure WS can be changed by vertical movement of the roll 3. Roll 3is positioned so that the wall structure WS is bent only a small amounteach time it is passed through the forming equipment. The first passthrough the rolls 1, 2, 3 puts a small amount of curvature in the wallstructure WS. Prior to each additional pass through the equipment, theroll 3 is moved higher so that it will put an additional small amount ofbend into the wall structure WS. Thus, the wall structure WS is movedthrough the rollers 1, 2, 3 several times until the desired radius ofcurvature is achieved. Each time, care is used to not bend the leadingand trailing portions 60, 62. This provides a flat portion in the uppersidewall regions of the box 10. If an attempt had been made to bend thewall structure WS the full amount in one pass, the webs 46, 48, 50 wouldmost likely collapse. However, it was found that the webs 46, 48, 50 canbe bent along with the skins 42, 44 if multiple passes are used and asmall amount of bending is done per each pass.

FIG. 3 shows the panels 56, 38, 40 spaced apart while they are in a bentcondition. This has been done for the purpose of making it easier to seethe construction of the box 10. However, as described above, the panels36, 38, 40 are welded together while in a flat condition. Then, thecombined structures 36, 38, 40 (wall structure WS above) is roll formedinto the desired shape. This shape is substantially semi cylindrical butwith upper side portions 60, 62 that are substantially flat.

The panel sections 36, 38, 40 are connected together by weld beads 56,58, one on each side of the structure. By way of example, the thicknessdimension T for the panel sections 36, 38, 40, may be substantiallyabout 1 ½ inches. The skins 42, 44 and webs 46, 48, 50 may besubstantially about 0.09 inches thick. The center-to-center dimensionbetween adjacent webs 46, 48, 50 may be substantially about 1.763inches. An important dimension is the thickness Z in the region of thewelds 56, 58. In the example, this thickness is substantially about0.188 inches. The weld recess width W is substantially about 0.250inches. The weld recess depth D is substantially about 0.125 inches.

In preferred construction, the edge walls or webs 48 are formed toinclude a longitudinally extending groove 54. The edge walls or webs 50are provided with a complementary longitudinally extending tongue 52. Asshown by FIG. 12, the tongue 52 makes a loose fit with the groove 54. Inthe given example, the tongue width may be substantially about 0.1875inches. The groove width may be substantially about 0.25 inches. Thetongue length may be about 0.1825 inches. The groove depth may besubstantially about 0.2475 inches. During assembly, two panel sectionsto be joined are brought together. The tongue 52 on one is inserted intothe groove 54 in the other. Then, the side planes of the two panelsections are put into substantial coplanar alignment and the weld beads56, 58 are placed within the weld recesses. The tongue and groovecomponents facilitate the welding process. If they were not present whenthe panels were welded together, the panels would expand and contractand become “wavy” down the length of the side. This would make itimpossible to weld properly. It would be possible to “tack” weld everytwelve inches on one side, but this would be impractical. The inventionincludes any type of tongue and groove system that holds the panelsparallel to each other for welding purposes. For example, a two tongueand two groove system could be used.

At each joint, the diagonal corner regions 64, 66 provide bothstructural reinforcement and width and depth for the weld beads 56, 58.A weld bead 56, 58 that is substantially triangular in cross section,substantially about 0.250 inches wide, and substantially about 0.125inches deep is made possible because of the thickness of the material inregions 64, 66. The corner regions 64, 66 and the weld beads 56, 50together form outwardly widening flanges that, together with the wallsections 48, 50 provide a reinforcing beam section at the location ofeach joint. This beam section extends the full length of the joint andits parts 48, 50, 64, 66 in effect form I-beam like longitudinalstiffening and strengthening ribs at each joint location.

The panels 36, 38, 40 that make up a sidewall are preferably laid flaton a jig. They are then clamped and tack welded about every four feet onthe underneath side. They are no tack welds on the top. Then, all panelsare welded the full length of the wall, simultaneously. The wall formingpanel assembly is then flipped over to position its welded side facingdownwardly. The wall structure is then clamped down and the new “up”side is welded the full length, simultaneously. As can be seen, there isno weld seams created that extend from one side of the wall structure tothe other. There is no need for longitudinal structural members forstrengthening the wall structure. The wall structure itself makes thisunnecessary.

The front wall 18 is preferably also made from panels that are composedof skins 42, 44 that are held spaced apart and are connected together bywebs 46, 48, 50. Referring to FIG. 2, the front wall 18 is shown, forexample, to be formed from panels 70, 72, 74, 76. Joints 78, 80, 82 areformed where the panels 70, 72, 74, 76 meet. These joints 78, 80, 82,are preferably like the joints shown in FIG. 4, and are composed of edgewebs, tongue-and-groove members, V-grooves for the welds, and weld beadsin the V-grooves.

The cylinder housing 32 is formed of sheet metal panels that are weldedtogether. Then, the housing 32 is placed within the box 10 and is weldedat its bottom edges to the panel 36 and at its rear edges to the wall18. An access window 84 is provided in the wall 18, to provide accessinto the cylinder housing 32.

A bottom opening 86 is provided in one or both of the panels 36, 38 toaccommodate the lower portion of the cylinder 24 as it extends throughthe bottom of the box 10 to an anchor location on the frame 12 below thebox 10. The upper edge or front wall 18 is preferably provided with acap 88. In similar fashion, on the opposite sides of the box 10, caps 90are connected to the upper edges of the sidewall portions 60, 62. Thecaps 10 keep dirt and water out of the extrusions. They are not providedfor strengthening the body. The strength of the rolled extrusionseliminates the need for a top rail that provides extra strength. An endcap 92 is preferably connected to the rear edge of the panel 40, toreinforce the rear edge and provide a stop for the door 20. Members 86,92 may be made from tubular stock while the members 90 are made fromchannel stock. The upper edge portions are received within a channelspace in the members 90.

In FIG. 3, the upper rear corner regions of the panel 40 are shown to benotched at 94, 96. Pin plates 98, 100 are received within the notches94, 96 and are welded to the panel 40. Pin plates 98, 100 are a part ofa pair of knuckle hinges which further include apertured plate pairs104, 106 at the upper corners of the door 20. Plates 98, 100 extendbetween the two plates of each pair 102, 104 and pivot pins are insertedthrough the three plates at each ends location to complete the hingestructure.

Door 20 is preferably also constructed from panels 106, 100, 110 thatare welded together where they meet.

FIGS. 5 and 6 relate to a larger box 112 mounted on a trailer chassis114. The box 112 is composed of sections 116-138, constructed andconnected together in the manner described above in connection with thefirst embodiment. These side portions of the box 112 includesubstantially flat upper portions and a cap structure 140. The front endof the box 112 includes an end wall 142. A door 144 is provided at therear of the box 112. The three adjacent sections 116, 118, 120 at therear of the box 112 are connected at their bottoms to a frame 146. Thisframe 146 is reinforced by gussets 148, 150, 152, 154 and it is hingeconnected at 156 to the frame 114. As shown by FIG. 6, a tippingcylinder 158 is provided at the front end of the box 112 and the frontend of the frame 114. A pair of bottom rails 160, 162 are provided atlaterally spaced apart locations on the bottom of the box 112. Theserails 160, 162 make contact with the chassis frame 114 when the box 112is supported by the chassis frame 114. The rails may comprise generallyC shaped extrusions which receive elastimeric bumper strips. Theelastimeric strips are receive in the extrusions. It is the elastimericstrips that make contact and prevent the aluminum from rubbing on theframe. The elastimeric strips also function as shock absorbers betweenthe frame and the aluminum. The extrusions and the elastimeric strips donot function to reenforce the aluminum body structure. As previouslystated, longitudinal supports and/or stiffeners are not needed becausethe side wall structure is stiffened by the skins and the webs thatextend between and interconnect the skins.

FIG. 7 is a sectional view taken through the section 136 of the box 112,substantially along line 7—7 of FIG. 5. It shows the thickness of theskins 160, 162 on an exaggerated scale relative to the web width 164.FIG. 7A is an enlarged scale of a portion of FIG. 7 that presents theparts 160, 162, 164 in a more realistic scale. Typical dimensions of theparts are stated above in the description of the first embodiment. FIG.7 shows upper side regions 166, 168 of the box 112 which aresubstantially flat. That is, the box structure 112 is substantiallystraight both vertically and horizontally in regions 166, 168. Belowregions 166, 168, the wall structure forming the box 112 has been rollformed to give it a concave inner side 170 and a convex outer side 172.Herein, the reference to the box structure being longitudinally straightand laterally curved applies even though the curvature stops below theupper sections 166, 168. The wall structure is predominantly curved inthe lateral direction because it has a concave inner side and a convexouter side even though the substantially flat sections 166, 168 arepresent.

The illustrated embodiments are only examples of the present inventionand, therefore, are non-limitive. It is to be understood that manychanges in the particular structure, materials and features of theinvention may be made without departing from the spirit and scope of theinvention. Therefore, it is my intention that my patent rights not belimited by the particular embodiments illustrated and described herein,but rather are to be determined by the following claims, interpretedaccording to accepted doctrines of patent claim interpretation,including use of the doctrine of equivalents and reversal of parts.

What is claimed is:
 1. A truck/trailer box construction, comprising: a horizontally straight sidewall structure having a vertically concave inside and a vertically convex outside; and said sidewall structure comprising spaced apart inner and outer skins and integral, longitudinally spaced apart vertical webs, extending between and interconnecting the two skins.
 2. The box construction of claim 1, wherein the inner and outer skins and the webs are constructed from an aluminum alloy.
 3. The box construction of claim 1, wherein the inner and outer skins and the webs are formed by extrusion.
 4. The box construction of claim 3, wherein the inner and outer skins and the vertical webs are constructed from an aluminum alloy.
 5. The box construction of claim 1, wherein the sidewall structure is formed from a longitudinal series of panels that are welded together at edges where they meet.
 6. The box construction of claim 5, wherein the panels are constructed from an aluminum alloy.
 7. The box construction of claim 1, wherein said sidewall structure has upper side portions that are both horizontally and vertically straight, said upper side portions being formed by upper portions of the inner and outer skins and by the transverse webs between the two skins.
 8. The box construction of claim 7, wherein the sidewall structure includes a pair of upper edges on opposite sides of the sidewall structure, and a longitudinal cap structure extending along each said edge. 